GLUTEAL REGION 301 



the inferior and superior gluteal arteries. The transverse 

 branch passes posteriorly, between the quadratus femoris and 

 the adductor magnus, and enters the hamstring muscles. It 

 anastomoses with the terminal twig of the middle division of 

 the lateral circumflex artery, which, in a well-injected subject, 

 will be noticed appearing from amidst the fibres of the proximal 

 part of the vastus lateralis. An arterial circle is thus com- 

 pleted, around the proximal part of the femur; it com- 

 municates proximally with the inferior gluteal artery and 

 distally with the first perforating artery. This series of in- 

 osculations is sometimes spoken of as the crucial anastomosis 

 of the thigh. 



The dissector has now examined all the structures in the 

 gluteal region which lie below the level of the piriformis. 

 He should, in the next place, turn his attention to that 

 portion of the dissection which lies above the level of 

 that muscle. There he will find several structures which lie 

 in close relation to the dorsum ilii. These are the glutaeus 

 medius, the glutaeus minimus, and the tensor fasciae latae, 

 together with the blood-vessels and nerve which supply them, 

 viz., the superior gluteal artery and vein, and the superior 

 gluteal nerve. 



The posterior part of the glutaeus medius muscle was 

 covered by the glutaeus maximus. Its anterior border is 

 overlapped by the tensor fasciae latae, and the intermediate 

 area is invested by the dense fascial layer already referred to. 



Dissection. Remove the fascia from the superficial surface 

 of the glutaeus medius and pull the tensor fasciae latae forward. 



M. Glutseus Medius. The glutaeus medius arises from 

 that part of the dorsum ilii which is bounded above by the 

 posterior curved line and the anterior four-fifths of the crest of 

 the ilium, and below by the anterior gluteal line (Fig. 128, 

 p. 286); it derives fibres also from the strong fascia which 

 covers it. The fibres converge to form a flattened band, 

 partly fleshy and partly tendinous, which is inserted into an 

 oblique line on the lateral aspect of the greater trochanter 

 of the femur, and into the surface immediately above it. 

 The glutaeus medius muscle is supplied by the superior gluteal 

 nerve. As a whole the muscle is an abductor of the thigh, 

 but its anterior fibres can rotate the thigh medially, and the 

 posterior fibres can rotate it laterally, 



